Lubricants and liquid hydrocarbon fuels containing synergistic mixtures of substituted tetrahydropyrimidines and amine salts of succinamic acids



United States Patent ABSTRACT OF THE DISCLOSURE Lubricants and liquid hydrocarbon fuels are provided containing a synergistic mixture of (1) A di-substituted tetrahydropyrimidine having the formula:

wherein R and R are aliphatic hydrocarbon radicals having from about 8 to about 22 carbon atoms, and from about 1 to about 22 carbon atoms, respectively, and

(2) An amine salt of (a) a succinamic acid having the formula:

wherein R is a monovalent aliphatic hydrocarbon radical containing from about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom, with (b) a primary monoalkyl amine, wherein the alkyl group contains from about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom.

This invention relates to improved organic compositions and, in one of its aspects, relates more particularly to improved organic compositions in the form of liquid and solid hydrocarbons that are normally susceptible to deterioration by corrosion or oxidation. Still more particularly, in this aspect, the invention relates to improved organic compositions in the form of petroleum distillate hydrocarbon fuels, lubricating oils and greases which, in their uninhibited state, tend to react with and corrode metal surfaces with which they may come into contact in performing their intended functions. I

It is well known that certain types of organic compounds are normally susceptible to deterioration by oxidation or by corrosion when coming into contact with various metal surfaces. For example, it is known that liquid hydrocarbons in the form of fuel oils or lubricating oils tend to accumulate considerable quantities of water when maintained for long periods of time in storage vessels; and when subsequently brought into contact with metal surfaces in their functional environments, deterioration of equipment as a result of corrosion, occurs. In addition, where such lubricating oils or other corrosioninducing materials are incorporated into solid lubricants as in the form of greases, similar deleterious results are encountered, thus clearly indicating the necessity for incorporating into such organic compositions an effective antioxidant and rust-inhibiting agent.

. Accordingly, it is an object of this invention to provide organic compositions having improved antioxidant and anti-corrosion properties.

Another object of the invention is to provide improved organic compositions in the form of liquid and solid hydrocarbons containing an additive which is adapted to prevent corrosion and oxidative deterioration of metallic surfaces.

Still another object of the invention is to provide an effective antioxidant and corrosion inhibiting agent for incorporation into the aforementioned organic compositions.

Other objects and advantages inherent in the invention will become apparent to those skilled in the art from the following more detailed description.

It has now been found that the aforementioned oxidative and corrosive properties of organic compositions, particularly in the form of fuels and lubricants, can be effectively overcome by incorporating therein, as an antioxidant and anti-corrosion agent, small amounts of an additive mixture comprising- (1) A til-substituted tetrahydropyrimidine having the formula:

wherein R and R are aliphatic hydrocarbon radicals having from about 8 to about 22 carbon atoms, and from about 1 to about 22 carbon atoms, respectively, and

(2) An amine salt of (a) a succinamic acid having the formula:

wherein R is a monovalent aliphatic hydrocarbon radical containing from about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom, with (b) a primary monoalkyl amine, wherein the alkyl group contains from about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom.

In general, the present invention, in its preferred applications, contemplates organic compositions which are normally susceptible to oxidative and corrosive deterioration, containing a small amount of the aforementioned additive mixture, usually from about .001 to about 10 percent, by weight, of the total of such compositions. When this additive is incorporated into liquid hydrocarbon compositions, such as jet fuels, turbine fuels, gasolines and the like, or in lubricating oils, it is preferably employed in an amount from about .001 to about .01 percent, by weight, of the total composition. When the additive is incorporated into a hydrocarbon grease composition, it is preferably employed in an amount from about 0.1 to about 5 percent, by weight, of the total grease.

The organic compounds improved in accordance with the present invention may comprise any materials that are normally susceptible to deterioration by oxidation or corrosion, in the manner previously described. A field of specific applicability is the improvement of liquid hydrocarbons in accordance with the present invention, boiling from about F. to about 750 F. Of particular significance is the treatment of petroleum distillate fuel oils having an initial boiling point from about 75 F. to about F. and an end boiling point from about 250 F. to about 750 F. It should be noted, in this respect, that the term distillate fuel oils is not intended to be restricted to straight-run distillate fractions. These distillate fuel oils can be straight-run distillate fuel oils, catalytically or thermally cracked (including hydrocracked) distillate fuel oils, or mixtures of straight-run distillate fuel oils, naphthas and the like, with cracked distillate stocks.

Moreover, such fuel oils can be treated in accordance with well-known commercial methods, such as acid or caustic treatment, hydrogenation, solvent-refining, clay treatment, and the like.

The distillate fuel oils are characterized by their relatively low viscosity, pour point and the like. The principal property which characterizes these contemplated hydrocarbons, however, is their distillation range. As hereinbefore indicated, this range will lie between about 75 F. and about 750 F. Obviously, the distillation range of each individual fuel oil will cover a narrower boiling range, falling, nevertheless, within the above-specified limits. Likewise, each fuel oil will boil substantially, continuously, throughout its distillation range.

Particularly contemplated among the fuel oils are Nos. 1, 2 and 3 fuel oils, used in heating and as Diesel fuel oils, gasoline and the jet combustion fuels, as previously indicated. The domestic fuel oils generally conform to the specifications set forth as ASTM Specification D396- 48T. Specifications for Diesel fuels are defined in ASTM Specification D975-48T. Typical jet fuels are defined in Military Specification MIL-F-5-624B. In addition, as previously indicated, hydrocarbon lubricating oils of varying viscosity and pour points, falling both within and outside the indicated ranges for the aforementioned fuel oils, may also be effectively treated through the use of the aforementioned additives, an antioxidation and anticorrosion agents.

As previously indicated, the aforementioned additives may also be incorporated, as anti-corrosion agents, in grease compositions. Such greases, may comprise a combination of a 'wide variety of lubricating vehicles and thickening or gelling agents. Thus, greases in which the aforementioned additives are particularly effective, may comprise any of the conventional hydrocarbon oils of lubricating viscosity, as the oil vehicle, and may include mineral or synthetic lubricating oils, aliphatic phosphates, esters and diesters, silicates, siloxanes and oxalkyl ethers and esters. Mineral lubricating oils, employed as the lubricating vehicle, may be of any suitable lubricating viscosity range from about 45 SSU at 100 F. to about 6,000 SSU at 100 F., and, preferably, from about 50 to about 250 SSU at 210 F. These oils may have viscosity indexes varying from below 0 to about 100 or higher. Viscosity indexes from about 70 to about 95 are preferred. The average molecular weights of these oils may range from about 250 to about 800. The lubricating oil is employed in the grease composition in an amount sufficient to constitute the balance of the total grease composition, after accounting for the desired quantity of the thickening agent, and other additive components to be included in the grease formulation.

As previously indicated, the oil vehicles employed in the novel grease formulations of the present invention, in which the aforementioned additives are incorporated as anti-oxidative or anti-corrosion agents, may comprise mineral or synthetic oils of lubricating viscosity. When high temperature stability is not a requirement of the finished grease, mineral oils having a viscosity of at least 40 SSU at 100 F., and particularly those fallingwithin the range from about 60 SSU to about 6,000 SSU at 100 F. may be employed. In instances, where synthetic vehicles are employed rather than mineral oils, or in combination therewith, as the lubricating vehicle, various compounds of this type may be successfully utilized. Typical synthetic vehicles include: polypropylene, propylene glycol, trimethylol propane esters, neopentyl and pentaerythritol esters, di (2-ethyl hexyl) sebacate, di-(Z-ethyl hexyl) adipate, di-butyl phthalate, fluorocarbons, silicate esters, silanes, esters of phosphorus-containing acids, liquid ureas, ferrocene derivatives, hydrogenated mineral oils, chain-type polyphenyls, siloxanes and silicones (polysiloxanes), alkyl-substituted diphenyl ethers typified by a butyl-substituted bis (p-phenoxy phenyl) ether, phenoxy phenyl ethers, etc.

The lubricating vehicles of the aforementioned improved greases of the present invention containing the above-described additive mixtures, are combined with a grease-forming quantity of a thickening agent. For this purpose, a wide variety of materials may be employed. These thickening or gelling agents may include any of the conventional metal salts or soaps, which are dispersed in the lubricating vehicle in grease-forming quantities, in such degree as to impart to the resulting grease composition, the desired consistency. Other thickening agents that may be employed-in the grease formation may comprise the non-soap thickeners, such as surface-modified clays and silicas, aryl ureas, calcium complexes and similar materials. In general, grease thickeners may be employed which do not melt and dissolve when used at the required temperature within a particular environment; however, in all other respects, any material which is normally employed for thickening or gelling hydrocarbon fluids for forming grease, can be used in preparing the aforementioned improved grease in accordance with the present invention.

The di-substituted tetrahydropyrimidine component of the novel additive mixtures of the present invention is prepared, in general, by condensing one mole of a straightchain carboxylic acid (either substituted or unsubstituted) having an aliphatic hydrocarbon radical, containing from about 1 to about 22 carbon atoms, with one mole of a straight-chain diamine, having an aliphatic hydrocarbon radical containing from about 8 to about 22 carbon atoms. The reaction may be represented by the following general equation:

CH: R-N CH] ZH'O RNHCHzCHzCHzNHI RlCOOH -r in which R is an aliphatic hydrocarbon radical having from about 8 to about 22 carbon atoms, and R is an aliphatic hydrocarbon radicaLhaving from about 1 to about 22 carbon atoms. The afore-mentioned condensation reaction is, in general, carried out at an elevated temperature, and, preferably, at a temperature from about 250 C. to about 310 C.

The following examples will serve to illustrate the pre aration of the aforementioned di-substituted tetrahydropyrimidine component of the novel additive mixtures of the present invention. It will be understood, of course, that it is not intended the invention be limited to the particular di-substituted tetrahydropyrimidine components shown, or to the operations or manipulations involved. Various modifications thereof, as previously described, can be employed and will be readily apparent to those skilled in the art.

Example 1 A mixture of 128 grams (0.5 mol) palmitic acid, 200 grams 0.5 mol) of a mixture of tallow N-alkyl tIimethylene diamines, containing aliphatic hydrocarbon radicals having from 16 to 18 carbon atoms (commercially available under the trade name Diam 26 and manufactured by General Mills) and grams of xylene, was refluxed at a temperature from about C. to about 250 C. for a period of about six hours. The temperature was maintained at 250" C. until the evolution of water had ceased. The resulting product comprised a mixture of tallow (C to C pentadecyl substituted tetrahydropyrimidines.

Example 2 A mixture of 200 grams (0.5 mol) of hydroxyphenyl stearic acid, 200 grams (0.5 mol) of the aforementioned Diam 26 of Example 1, and 100 grams of xylene, was refiuxed at a temperature from about 140 C. to about 280 C. for a period of about six hours. The temperature was maintained at 280 C. until the evolution of waterhad ceased. The resulting product comprised a mixture of tallow (C to C hydroxyphenylheptadecyl substituted tetrahydropyrimidines.

Example 3 A mixture of 130 grams (0.5 mol) palmitic acid, 200 grams (0.5 mol) of oleyl diamine (commercially available under the trade name Formonyte 808 and manufactured by Foremost Food and Chemical Co.), and 100 grams of xylene, was refluxed at a temperature from about 140 C. to about 260 C. for a period of about six hours. The temperature was maintained at 260 C. until the evolution of water had ceased. The resulting product was an oleyl pentadecyl substituted tetrahydropyrimidine.

Example 4 A mixture of 151 grams (0.53 mol) of oleic acid, 207 grams (0.53 mol) of the aforementioned Formonyte 808 of Example 3, and 100 grams of xylene, was refluxed at a temperature from about 140 C. to about 260 C. for a period of about six hours. The temperature was maintained at 260 C. until the evolution of water had ceased. The resulting product was an oleylheptadecenyl substituted tetrahydropynimidine.

7 Example 5 Example 6 A mixture of 128 grams (0.5 mol) palmitic acid, 200 grams (0.5 mol) of N aminopropyl oleyl amine, and 100 grams of xylene was refluxed at a temperature from about 140 -C. to-about 290 C. for a period of about eight hours. The temperature was maintained at 290 C. until the evolution of water had ceased. The resulting product was a pentadecyl substituted tetrahydropyrirnidine.

The other'component of the novel additive mixtures of the present invention, as indicated above, namely the amine salt of the aforementioned succinamic acid (a) and the primary monoalkyl amine (b), is, in general, prepared by reacting, at elevated temperature, succinic acid anhydride with a primary monoalk-yl amine having a tertiary carbon atom attached to the nitrogen atom, and containing from about 4 to about 30, and preferably from about 12 to about 15, carbon atoms per molecule, to form the corresponding succinamic acid. The succinamic acid, thus produced, is then reacted, at elevated temperature, with an additional quantity of the aforementioned amine to form the corresponding amine salt. A more detailed description for the preparation of the amine salt, compound (2) of the additive mixtures of the present invention, is set forth in US. Patent No. 3,031,282, and the descriptive matter pertinent thereto, is incorporated in the present application by reference.

As indicated above, the novel additives of the present invention comprise mixtures of the aforementioned (l) the'disubstituted tetrahydropyrimidine, and (2) the amine salt of the aforementioned succinamic acid and primary monoalkyl amine. In this respect, it is found that although 'pronouncedly, more than merely additive. In this respect,

this synergistic effect is observed with any ratio of componcnts ('1) and (2) being present in combination. A particularly effective additive agent comprises a mixture in which components (1) and (2) are individually present in an amount from about 10 to about percent, by weight, of the additive mixture. I

The following examples will serve to illustrate the synergistic eflect of the aforementioned components (1) and (2) in the novel additive mixtures of the present invention, in inhibiting deterioration of organic compositions and, particularly, with respect to hydrocarbon fuels. Component (2) in the examples comprised a mixture of amine salts produced by reacting a mixture of the aforementioned succinamic acids (a), wherein R was a monovalent aliphatic hydrocarbon radical containing from about 12 to about 15 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom, with a mixture of :primary monoalkyl amines (b), wherein the alkyl group contained from about 12 to about 15 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom.

The improvement that is provided by the practice of this invention with respect to inhibiting gasoline against formation of carburetor deposits, by the aforementioned synergistic effect of mixtures of components (1) and (2) is determined by the following Carburetor Detergency Test:

The deposit-forming tendencies of a fuel are determined in an 8-hour engine test. This accelerated test, when run on fuels that contain no detergents, produces an amount of deposit equivalent to the amount observed in 4,000 miles of operation in field tests on taxicab fleets. A sixcylinder Chevrolet engine is equipped with notched rings to increase the amount of blowby. Engine is operated for 8 hours, using the fuel under test, at alternate idle and running cycles. In the idle cycle, the engine is run at idling speed of 400 r.p.m. with no load, for five minutes. Then, for one minute, the engine is run at a speed of 2500 r.p.m. under a load of 30 B.H.P. and at 9.4 in mercury manifold pressure. During the running cycle, the blowby and part of the exhaust are released into the carburetor air intake during the idling cycle. After 8 hours operation at alternate run and idle, the carburetor is examined and rated as to the amount of deposit in the throttle throat. In the rating scale, a rating of 0 (zero) indicates a clean carburetor; 1=trace deposits; 2=light deposits; 3=medium deposits; and 4=heavy deposits.

CARB URETOR DETERGENCY 'IES'I.EIGHT HOUR TEST WITH PYREX THROTTLE BODY [Additives blended in a gasoline fuel comprising eatalytically cracked eomponents-approximateiy 90-310 F. boiling range] Cone. lbs/1,000 bbls. Cleanliness Rating Example 7:

Base gasoline 0 Base gasoline plus Ex. 1. 4 Base gasoline plus 6 Component (2). Base gasoline plus Ex. 1 [2 lbs. each of Ex. 1

plus Component (2 and Component (2)].

Example 8:

Base gasoline 0 Base gasoline plus Ex. 3... 4.

Base gasoline plus 6 Component (2).

Base gasoline plus Ex. 3 plus Component (2).

Example 9:

Base gasoline 0 Base gasoline plus Ex. 5. 4

Base gasoline plus 6 Component (2).

Base gasoline plus Ex. 5 plus Component (2).

Example 10:

Base gasoline 0 Base gasoline plus Ex. 6-- 4 Base gasoline plus 6 Component (2).

Base gasoline plus Ex. 6 plus Component (2).

P 2"?!" a: usual [2 lbs. each of Ex. 3

and Component (2)].

[2 lbs. each of Ex. 5

and Component (2)].

[2 lbs. each of Ex. 6

and Component (2)].

mixtures of the addition agents of the present invention, to determine their effectiveness as anti-rust agents. These tests were carried out under the conditions of ASTM Rust Test D-665, operated for a period of 48 hours at 80 F., employing distilled water.

Cone. lbs/1,000 bbls. Rust Rating Example 11:

B859 ea Alina Severe rust. Base gasoline plus Ex. 1--.. 6 0. Base gasoline plus Corn- 6 Light rust.

ponent (2). Base gasoline plus Ex. 1 plus Component (2). Example 12:

[3 lbs. each of Ex. 1 and No rust.

Component (2) .1

Base gasoline 0 Severe rust.

Base gasoline plus Ex. 2-.-. 6-..- Do.

Base gasoline plus Com- 6 Light rust.

ponent (2).

Base gasoline plus Ex. 2 plus Component (2). Example 13:

Base gasoline 0 Severe rust. Base gasoline plus Ex 3.... 6-.-- 0. Base gasoline plus Com- 6 Light rust.

ponent (2). Base gasoline plus Ex. 3 [3 lbs. each of Ex. 3 and No rust.

plus Component (2). Component (2).] Example 14:

Base gasoline 0 Severe rust. Base gasoline plus Ex 4.-. 6 0. Base gasoline plus Com- 6 Light rust.

poneut (2). Base gasoline plus Ex. 4 [3 lbs. each of Ex. 4 and No rust.

plus Component (2). Component (2).]

[3 lbs. each of Ex. 2 and No rust.

Component (2) .1

Example 15:

Base gasoline 0..- Severe rust. Base gasoline plus Ex. 10. 0. Base gasoline plus Com- 6--.- Light rust.

ponent (2). Base gasoline plus Ex. 6 [3 lbs. each of Ex. No rust.

plus Component (2). and Component (2).] Example 16:

Base on. nlina 0 Severe [118t- Base gasoline plus Ex. 6.--- 6---" Do. Base gasoline plus Com- 6.-.. Light rust.

ponent (2). Base gasoline plus Ex. 6 plus Component (2).

[2 lbs. each of Ex. 6 and No rust.

Component (2) .1

As is apparent from the data in Examples 11 through 16, synergistic mixture of the addition agents of the present invention are effective in inhibiting gasoline fuels against rusting.

From the foregoing it will be apparent that the aforementioned synergistic mixtures of di-substituted tetrahydropyrimidines and the amine salts, of the present invention, are markedly effective in inhibiting deterioration of organic compositions, and particularly effective with respect to the treatment of such hydrocarbons as petroleum distillate fuels.

Furthermore, although the present invention has been described with preferred embodiments, it will be understood that modifications and variations thereof may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand.

We claim:

1. Organic compositions selected from the group consisting of lubricants and liquid hydrocarbon fuels containing a small amount, sufiicient to inhibit corrosion, of a synergistic mixture consisting essentially of from about to about 90% by weight of each of:

(l) a di-substituted tetrahydropyrimidine, having the formula:

IHYI/ I and wherein R is a monovalent aliphatic hydrocarbon radical containing from about 4 to about 30'carbon atoms and having a tertiary carbon atom directly attached. to the nitrogen atom, with (b) a'primary monoalkyl amine, wherein the alkyl group contains from-about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom.

2. A composition in accordance with claim 1 wherein the monovalent aliphatic hydrocarbon radical recited in component (a) and the alkyl group recited in component (b), of said mixture, each contains from about 12 to about 15 carbon atoms.

3. A composition in accordance with claim 1 wherein said mixture is present in an amount from about .001 to about 10 percent, by weight, of the total of said composition.

4. A composition in accordance with claim 1 wherein said mixture is present in an amount from about .001 to about .01 percent, by weight, of the total of said composition.

5. A composition in accordance with claim 1 wherein said mixture is present in an amount from about 0.1 to about 5 percent, by weight, of the total of said composition. 0

6. A composition in accordance with claim 1 wherein said composition comprises a lubricant.

7. A composition in accordance with claim 1 wherein said composition comprises a grease.

' 8. A composition in accordance with claim 1 wherein said composition is a liquid hydrocarbon comprising a petroleum distillate fuel oil having an initial boiling point from'about 75 F. to about t35 F. and an endboiling point from about 250 F. to about 750 F.

(I) a di-substituted tetrahydropyrimidine, having the formula:

wherein R and R are aliphatic hydrocarbon-radicals having from about 8 to about 22 carbon atoms, and from about 1 to about 22 carbon atoms, respectively,

and

(2) an amine salt of (a) a succinamic acid having the formula:

0 BNH-C-CHs-CHs-C I OH wherein R is a monovalent aliphatic hydrocarbon-radical containing from about 4 to about 30 carbon atoms-and having a tertiary carbon atom directly attached to. the

nitrogen atom, with (b) a primary monoalkyl amine,

wherein the alkyl group contains from about 4 to about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom.

13. The composition of claim 12 wherein the monovalent aliphatic hydrocarbon radical recited in component (a) and the alkyl group recited in component (b) each contains from about 12 to about 15 carbon atoms.

References Cited UNITED STATES PATENTS 1/1955 Smith et a1. 25233.6 7/1958 Cyba et a1. 4463 PATRICK P. GARVIN, Primary Examiner. 

